Daniel deawbatjgh



(No Model.)

DRAWBAUGH. TELEPHONE TRANSMITTER. I NQLZ lTBIL, I L Patented-Jan. 1,1884.

iii M INVENTOR BY v T W ATTORNEYS diaphragm, which may be of wood.

.UNirEn STATES PATENT FFICE.

DANIEL DRAXVBAUGH, OF EBERLYS MILLS, PENNSYLVANIA, ASSIGNOR TO THE PEOPLES TELEPHONE COMPANY, OF NEW YORK.

TELEPH O NE-TRANSMlTTER.

SPECIFICATION forming part of Letters Patent No. 291,311, dated January 1, 1884.

Application filed March 24, 1853. (No model l .To all whom, it may concern:

Be it known that I, DANIEL DRAWBAUGH,

of Eberlys Mills, Cumberland county, Pennsylvania, have invented a new and useful Im- 5 provement in Telephone Transmitters, of

which the following is a specification.

This invention relates to that class of telephones commonly known as carbon transmitters.

The invention consists in the construction of the instrument more particularly hereinafter set forth and in the devices described, whereby the carbons may be moved out of contact, or into very delicate contact, or into less delicate contact, as may be desired. By this an rangement the instrument may be rendered inoperative or capable of transmitting any noise for the purpose of sounding an alarmsignal in the receiving-instrument, or capable of use as a transmitter of vocal speech.

In the accompanying drawings, Figure 1 is an elevation of the instrument with the back board removed, thus showing the rear side of the diaphragm. Fig. 2 is a section on the line X Xof Fig. 1. Fig. 3 is a section on the line Y Y of Fig. 1. Fig. 4is a sectional enlarged view of the carbons and their attachments on the line Z Z of Fig. 1.

Similar letters of reference indicate like parts.

A is the case of the instrument.

B is the O is the outer cover, having a mouth-piece orifice, D. To the rear of the diaphragmand at about its center is attached a'brass plate, E, which supportsa brass cup, F. In this cup is placed an annular cupshaped piece of carbon or other low conducting material, G. In the hollow of carbon G aball, H, of carbon or other low conducting material, is adapted to rest. Through this ball passes a metal rod, I, the ball resting 011 a shoulder of the rod, as shown in Fig. 4. The ball is rigidly fastened to the rod. Said rod extends downwardly through a central opening in the carbon G and cup F. Beneath its lower end is arranged a plate of metal, J, having paper or other insulating material on its upper surface. Said plate is supported by a stem, K, rigidly secured to a fiat spring, L, which is fastened to thebottom of the case.

0. To the bottom of the case is also attached 5 a hook, I, to receive the ring Q of a receiv ing-instrument or other object, which may be hungthereon. To the side of the case is attached a fiat spring, 1%, which communicates with apressbutton, S, the stem of which passes through the side of the case. WVheu this press-button S is pushed in, the end of the spring R is brought into contact with the bent end T of the spring M.

The operation of the instrument is as follows: 6 WVhen the ring Q of the receiving-instrument is removed from the hook I, the spring L and plate J assume their lowest position. In such case the plate J and rod I are not in contact. The ball H then rests with its whole weight, plus that of the rod I, upon the carbon G. The spring M takes no part in pressing the carbon ball down into the cup G, as when the ball rests, as above described, in said cup the spring M and the upper end of rod I are out of contact. The instrument is then adapted for use for transmitting speech, and the course of the circuits is as follows: Proceeding from the battery to the binding-post 1, the current passes by the wire a to the rod I and ball H, thence to the carbon cup G, metal cup F, plate E, wire I), to the primary of the induction-coil U, thence by the wire 0 to the binding-post 2, and so to the battery again. The secondary wires (1 and e of the induction-coil U lead to the posts 3 and 4, which connect to the line.

In order to render the instrument very delicate, so that the carbon ball and cup may be in very light contact, I support the carbon ball from below, so that only a small portion 9 of its weight may fall upon the carbon cup beneath. This I do by raising the plate J so that it shall come in contact with the end of the rod I and lift said rod slightly. As the rod I has some play in its aperture in the carbon cup it moves slightly sidewise, so that the ball does nottouch the cup around its whole circumference. I find it convenient to raise this plate J, and hold it raised, by introducing the ring Q, of the receiving-instrument, or any other object of suitable size, between the hook P and horizontal projection O of the spring L. I cut away or curve the under side of the projection O at V, so that when the ring Q is introduced between the hook P and spring 0 to about this point V it will have raised the spring L and plate K, and consequently the rod Lsuffieiently to bring the carbon ball H into the desired light contact with the carbon cup G. When the ring Q or other object is pushed in between the hook P and the spring-arm 0 all the way, or to the point indicated in the draw ings, Fig. 2, then the plate J and the ball H are raised to the positions indicated by dotted lines in said figure and Fig. 4. In such case it will be seen that the carbons are wholly out of contact when the instrument is no longer operative for transmitting sound. It is then, however, in a condition for signaling, as follows: The battery-current, entering at binding-post 1, proceeds by the wire a to the rod I, and thence directly to the spring M, which is now in contact with the upper end of rod I, when the press-button S is pushed in to close the circuit. The current continues along the spring R, and thence passes, by the wire f, to the wire 9, and thence to the line by the binding-post 4. The other pole of the battery connects with the binding-post 2, which, by means of the wire 72, communicates with the line binding-post 3. The branch wiresz' andg connect the secondary wire d c and line binding-post 3 and at with the binding-post 5 and 6, to which a receiving-instrument may be attached.

I claim as my invention- 1. In a telephone, the combination of two electrodes of low conducting material, respectively in the shape of an annular cup or socket, and of a ball adapted to be received in said cup or socket, and means for raising and holding said ball out of contact with said cup, substantially as described.

2. In a telephone, the combination of a diaphragm, an annular cup or socket of low conducting-material, supported by or upon said diaphragm, a ball of low conducting material adapted to be received in said cup, and a metallic rod fastened to said ball and passing through the aperture in said cup, substantially as described.

3. In a telephone, the combination of a nonconducting diaphragm, a conducting-support attached thereto, an annular cup or socket of low conducting material held in said support, a ball of low conducting material adapted to be received in said cup, and a metallic rod fastened to said ball and passing through the aperture in said on p, substantially as described.

4. In atelephone, the combination of a nonconducting diaphragm, a conducting support attached thereto, an annular cup or socket of low conducting material, a ball of low conducting material adapted to be received in said cup, a rod attached to said ball and extending downward through the aperture in said cup, and a vertically movable support arranged beneath the lower end of said rod and capable of being elevated to meet said rod and lift or sustain the same, substantially as described.

5. The combination, in a telephone, of the ball H, annular cup-shaped carbon G, the support E F, rod I, plate J, spring L, and hook or bracket P, connected in circuit, substantially as described. V

6. The combination, in a telephone, of the rod I, support E F, spring M, button S. and spring R, connected in circuit, substantially as described.

DANIEL DRAYVBAUGH.

Vitnesses:

W. H. CLENDENIN, JOHN L. SHELLEY. 

